Electric signaling.



R. A. PESSENDEN.

ELECTRIC SIGNALING.

APPLICATION FILED 00131, 1907 1513,56. Patented Mar. 23, 1915.

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following is a specification.

" in connection with a method for generating electromagnetic waves practically cont1nu-' UNITED STATES PATENT OFFICE.

REGINALD A. FESSENDEN, OF BRANT ROCK, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, T0 SAMUEL M. KINTNER, 'OF PITTSBURGH, PENNSYLVANIA, AND HALSEY M. BARRETT, OF BLOOMFIELD, NEW JERSEY, RECEIVER",

ELECTRIC SIGNALING.

Specification of Letters Patent. P t t 23. 1915 Application filed October 31, 1907. Serial No. 400132.

To all whom it may concern Be it known that I, REGINALD A. FESSEN- DEN, a citizen of the United States, residing at Brant Rock, in the county of Plymouth, State of Massachusetts, have invented certain new and useful Improvements in Electric Signaling, of which improvements the My invention relates to method of and apparatus for high speed si morfieparticularly high speed wireless telegra Y In the accompanying drawings forming a part of this specification Figure 1 shows apparatus for sending and Fig. 2 apparatus for receiving embodying my invention.

The invention herein described has for its object the transmission and receipt of a large number of words per minute between si aling stations.

n the practice of my invention I prefer to use an ordinary Wheatstone transmitter ously at the sending end and to make the perforated tape change the frequency of the waves without interrupting their con: tinuity. At the receiving end I prefer to use my heterodyne receiver as more fully described in my Patent No. 1,050,441, Jan. 14, 1913, though any other suitable type may be used and to record the sound produced on a phonograph of any type, such as the Poulsen or Edison phonograph.

The messages onrbeing received at the sending end are transferred to the. perforated tape which is sent through the machine at a high rate of speed, for example 500 words per minute. The phonograph at the receiving end is run at a speed muchabove normal, for example 20 revolutions per second, while the message is being received. The phonograph .record is then handed to an operator who by running at a speed of say one revolution per second gets the telegraph messages at the rate of of continuous current, 17 an adjustable realing and sistance, the whole forming a system for producing practically continuous high frequency oscillations as described in U. S. Patent 706,742.

18 is a Vheatstone transmitter, 19 being a strip of perforated paper on which the message is embossed and 20 the relay'of the Wheatstone transmitter.

The relay of the Wheatstone transmitter operates to cut out the portion 21 of the inductance 14, thus changing the frequency of the emitted waves by a small amount, preferably about a of one per cent.

In Fig. 2, 22 is the antenna, grounded at 23; 24-, 25 the primary and secondary of a transformer, 26 is a small coil mounted on a telephone diaphragm 27, 28 an electromagnet excited by a source of high frequency currents of nearly the same frequency as the received waves, such-for example as a high frequency alternator 29. This will cause beats with the received oscillations in cases where this is desired or necessary, and such beats effect the diaphragm 27 as will be evident. 30 is a phonograph trumpet and 40 a phonograph of the Edison type.

41 is a receiver, with a rubber-ear piece 42, which can be attached to the phonograph to determine if the messages are being recorded.

If desired the phonograph needle may be mounted directly on the diaphragm 27, but as this modification is an obvious equivalent it is not shown. 1

It is found that by using the. present apparatus in the manner described the effects of static disturbances are eliminated. Such disturbances are almost invariably pulses of low frequency, say 40 or 50 per second.

If the signaling Waves are emitted at a high spark or group frequency, say 10,000 per second, they can be recorded at the same speed with the static disturbances of a frequency of from 40 to 50 or the like super-v Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is the following 1. The method of electric signaling, which comprises sending the signaling waves at high frequency, recording said waves along with the efiects of disturbing pulses, and then reproducing the record at a lower speed, whereby the efiect of the disturbing impulse is eliminated.

2. The method of wireless signaling, which comprises sending the. signaling waves at high frequency, recording said waves and the effects of disturbing impulses at high speed, and then reproducing the record at a speed so low as to eliminate the effect of the disturbing impulse but leaving the signaling waves audible.

messes REGINALD A. FESSENDEN. Witnesses:

Jnssm E. BENT, AnnLnrNn Woman.

to eliminate the efiect of the disturb- 

